Total knee arthroplasty (TKA) is one of the most common surgical procedures performed in the U.S., and rates are rising rapidly. TKA results in decreased pain, increased range of motion, and improvements in some aspects of physical function for most patients. However, accumulating evidence shows that patients have persistent deficits in other critical outcomes following TKA. First, the majority of patients do not substantially increase physical activity beyond levels prior to TKA, remaining well below recommended levels. This has negative implications for both joint health and overall health. Second, gait asymmetries are common following TKA, such that patients often continue to load the non-surgical leg more heavily during walking, even when the post-surgical leg is pain free, placing the contralateral limb at risk for developing or worsening osteoarthritis. Our long-term objective is to improve post-TKA outcomes, particularly overall physical activity and joint loading symmetry, through implementation of a rehabilitation process that directly addresses these core domains. The objective of the proposed study is to conduct an exploratory trial of a novel Physical Activity and Symmetry (PAS) intervention, which addresses these persistent post-TKA deficits in the context of routine post-TKA physical therapy. The study specifically aims to obtain preliminary data on the efficacy of the PAS intervention, with respect to changes in: 1) objectively assessed physical activity and 2) peak load symmetry during gait using a novel insole device. The study will also assess the feasibility and acceptability of the PAS intervention. The trial will involve 72 patients enrolled during the course of routine post-TKA physical therapy who will be randomized either to the PAS intervention or an attention control group. The PAS intervention will be initiated by the treating physical therapist during the final visits of traditional in-person PT and will be continued via a phone call after four weeks and an in-person visit after eight weeks to monitor progress, address barriers to engagement, and advise on exercise modifications. The PAS intervention will utilize evidence-based strategies of brief motivational interviewing, goal-setting and connection with appropriate resources to assist participants with progressively increasing overall physical activity levels. Tailored balance exercises will be used to address joint loading asymmetries. Outcomes will be assessed at baseline, eight weeks (following completion of PAS), and 6 months. This exploratory study will provide essential information to guide a larger, multi-site randomized controlled trial of the PAS intervention.